mirrors/gstreamer
mirrors/gstreamer
1
1
Fork 0
mirror of https://gitlab.freedesktop.org/gstreamer/gstreamer.git synced 2024-11-27 20:21:24 +00:00
Code Issues 1 Projects Releases Wiki Activity
gstreamer/subprojects/gst-plugins-bad/gst-libs/gst/codecparsers/gstmpegvideoparser.c

1071 lines
29 KiB
C
Raw Blame History

/* Gstreamer
* Copyright (C) <2011> Intel Corporation
* Copyright (C) <2011> Collabora Ltd.
* Copyright (C) <2011> Thibault Saunier <thibault.saunier@collabora.com>
*
* From bad/sys/vdpau/mpeg/mpegutil.c:
* Copyright (C) <2007> Jan Schmidt <thaytan@mad.scientist.com>
* Copyright (C) <2009> Carl-Anton Ingmarsson <ca.ingmarsson@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstmpegvideoparser
* @title: GstMpegvideoParser
* @short_description: Convenience library for mpeg1 and 2 video
* bitstream parsing.
*
* Provides useful functions for mpeg videos bitstream parsing.
*
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "gstmpegvideoparser.h"
#include "parserutils.h"
#include <string.h>
#include <gst/base/gstbitreader.h>
#include <gst/base/gstbytereader.h>
#define MARKER_BIT 0x1
/* default intra quant matrix, in zig-zag order */
static const guint8 default_intra_quantizer_matrix[64] = {
8,
16, 16,
19, 16, 19,
22, 22, 22, 22,
22, 22, 26, 24, 26,
27, 27, 27, 26, 26, 26,
26, 27, 27, 27, 29, 29, 29,
34, 34, 34, 29, 29, 29, 27, 27,
29, 29, 32, 32, 34, 34, 37,
38, 37, 35, 35, 34, 35,
38, 38, 40, 40, 40,
48, 48, 46, 46,
56, 56, 58,
69, 69,
83
};
static const guint8 mpeg_zigzag_8x8[64] = {
0, 1, 8, 16, 9, 2, 3, 10,
17, 24, 32, 25, 18, 11, 4, 5,
12, 19, 26, 33, 40, 48, 41, 34,
27, 20, 13, 6, 7, 14, 21, 28,
35, 42, 49, 56, 57, 50, 43, 36,
29, 22, 15, 23, 30, 37, 44, 51,
58, 59, 52, 45, 38, 31, 39, 46,
53, 60, 61, 54, 47, 55, 62, 63
};
enum
{
GST_MPEG_VIDEO_MACROBLOCK_ESCAPE = G_MAXUINT,
};
/* Table B-1: Variable length codes for macroblock_address_increment */
static const VLCTable mpeg2_mbaddr_vlc_table[] = {
{1, 0x01, 1},
{2, 0x03, 3},
{3, 0x02, 3},
{4, 0x03, 4},
{5, 0x02, 4},
{6, 0x03, 5},
{7, 0x02, 5},
{8, 0x07, 7},
{9, 0x06, 7},
{10, 0x0b, 8},
{11, 0x0a, 8},
{12, 0x09, 8},
{13, 0x08, 8},
{14, 0x07, 8},
{15, 0x06, 8},
{16, 0x17, 10},
{17, 0x16, 10},
{18, 0x15, 10},
{19, 0x14, 10},
{20, 0x13, 10},
{21, 0x12, 10},
{22, 0x23, 11},
{23, 0x22, 11},
{24, 0x21, 11},
{25, 0x20, 11},
{26, 0x1f, 11},
{27, 0x1e, 11},
{28, 0x1d, 11},
{29, 0x1c, 11},
{30, 0x1b, 11},
{31, 0x1a, 11},
{32, 0x19, 11},
{33, 0x18, 11},
{GST_MPEG_VIDEO_MACROBLOCK_ESCAPE, 0x08, 11}
};
#ifndef GST_DISABLE_GST_DEBUG
#define GST_CAT_DEFAULT gst_mpegvideo_debug_category_get()
static GstDebugCategory *
gst_mpegvideo_debug_category_get (void)
{
static gsize cat_gonce = 0;
if (g_once_init_enter (&cat_gonce)) {
GstDebugCategory *cat = NULL;
GST_DEBUG_CATEGORY_INIT (cat, "codecparsers_mpegvideo", 0,
"mpegvideo parser library");
g_once_init_leave (&cat_gonce, (gsize) cat);
}
return (GstDebugCategory *) cat_gonce;
}
#endif /* GST_DISABLE_GST_DEBUG */
/* Set the Pixel Aspect Ratio in our hdr from a ASR code in the data */
static void
set_par_from_asr_mpeg1 (GstMpegVideoSequenceHdr * seqhdr, guint8 asr_code)
{
int ratios[16][2] = {
{0, 0}, /* 0, Invalid */
{1, 1}, /* 1, 1.0 */
{10000, 6735}, /* 2, 0.6735 */
{64, 45}, /* 3, 0.7031 16:9 625 line */
{10000, 7615}, /* 4, 0.7615 */
{10000, 8055}, /* 5, 0.8055 */
{32, 27}, /* 6, 0.8437 */
{10000, 8935}, /* 7, 0.8935 */
{10000, 9375}, /* 8, 0.9375 */
{10000, 9815}, /* 9, 0.9815 */
{10000, 10255}, /* 10, 1.0255 */
{10000, 10695}, /* 11, 1.0695 */
{8, 9}, /* 12, 1.125 */
{10000, 11575}, /* 13, 1.1575 */
{10000, 12015}, /* 14, 1.2015 */
{0, 0}, /* 15, invalid */
};
asr_code &= 0xf;
seqhdr->par_w = ratios[asr_code][0];
seqhdr->par_h = ratios[asr_code][1];
}
static void
set_fps_from_code (GstMpegVideoSequenceHdr * seqhdr, guint8 fps_code)
{
const gint framerates[][2] = {
{30, 1}, {24000, 1001}, {24, 1}, {25, 1},
{30000, 1001}, {30, 1}, {50, 1}, {60000, 1001},
{60, 1}, {30, 1}
};
if (fps_code && fps_code < 10) {
seqhdr->fps_n = framerates[fps_code][0];
seqhdr->fps_d = framerates[fps_code][1];
} else {
GST_DEBUG ("unknown/invalid frame_rate_code %d", fps_code);
/* Force a valid framerate */
/* FIXME or should this be kept unknown ?? */
seqhdr->fps_n = 30000;
seqhdr->fps_d = 1001;
}
}
/* @size and @offset are wrt current reader position */
static inline gint
scan_for_start_codes (const GstByteReader * reader, guint offset, guint size)
{
const guint8 *data;
guint i = 0;
g_assert ((guint64) offset + size <= reader->size - reader->byte);
/* we can't find the pattern with less than 4 bytes */
if (G_UNLIKELY (size < 4))
return -1;
data = reader->data + reader->byte + offset;
while (i <= (size - 4)) {
if (data[i + 2] > 1) {
i += 3;
} else if (data[i + 1]) {
i += 2;
} else if (data[i] || data[i + 2] != 1) {
i++;
} else {
break;
}
}
if (i <= (size - 4))
return offset + i;
/* nothing found */
return -1;
}
/****** API *******/
/**
* gst_mpeg_video_parse:
* @packet: a #GstMpegVideoPacket to fill with the data and offset of the
* next packet found
* @data: The data to parse
* @size: The size of @data
* @offset: The offset from which to start parsing
*
* Parses the MPEG 1/2 video bitstream contained in @data, and returns the
* offset, and if known also the size, in @packet. This function will scan
* the data to find the next packet if needed.
*
* Returns: TRUE if a packet start code was found, otherwise FALSE.
*/
gboolean
gst_mpeg_video_parse (GstMpegVideoPacket * packet,
const guint8 * data, gsize size, guint offset)
{
gint off;
GstByteReader br;
if (size <= offset) {
GST_DEBUG ("Can't parse from offset %d, buffer is to small", offset);
return FALSE;
}
size -= offset;
gst_byte_reader_init (&br, &data[offset], size);
off = scan_for_start_codes (&br, 0, size);
if (off < 0) {
GST_DEBUG ("No start code prefix in this buffer");
return FALSE;
}
if (gst_byte_reader_skip (&br, off + 3) == FALSE)
goto failed;
if (gst_byte_reader_get_uint8 (&br, &packet->type) == FALSE)
goto failed;
packet->data = data;
packet->offset = offset + off + 4;
packet->size = -1;
/* try to find end of packet */
size -= off + 4;
off = scan_for_start_codes (&br, 0, size);
if (off >= 0)
packet->size = off;
return TRUE;
failed:
{
GST_WARNING ("Failed to parse");
return FALSE;
}
}
/**
* gst_mpeg_video_packet_parse_sequence_header:
* @packet: The #GstMpegVideoPacket that carries the data
* @seqhdr: (out): The #GstMpegVideoSequenceHdr structure to fill
*
* Parses the @seqhdr MPEG Video Sequence Header structure members
* from video @packet
*
* Returns: %TRUE if the seqhdr could be parsed correctly, %FALSE otherwise.
*
* Since: 1.2
*/
gboolean
gst_mpeg_video_packet_parse_sequence_header (const GstMpegVideoPacket * packet,
GstMpegVideoSequenceHdr * seqhdr)
{
GstBitReader br;
guint8 bits;
g_return_val_if_fail (seqhdr != NULL, FALSE);
if (packet->size < 8)
return FALSE;
gst_bit_reader_init (&br, &packet->data[packet->offset], packet->size);
/* Setting the height/width codes */
READ_UINT16 (&br, seqhdr->width, 12);
READ_UINT16 (&br, seqhdr->height, 12);
READ_UINT8 (&br, seqhdr->aspect_ratio_info, 4);
/* Interpret PAR according to MPEG-1. Needs to be reinterpreted
* later, if a sequence_display extension is seen */
set_par_from_asr_mpeg1 (seqhdr, seqhdr->aspect_ratio_info);
READ_UINT8 (&br, seqhdr->frame_rate_code, 4);
set_fps_from_code (seqhdr, seqhdr->frame_rate_code);
READ_UINT32 (&br, seqhdr->bitrate_value, 18);
if (seqhdr->bitrate_value == 0x3ffff) {
/* VBR stream */
seqhdr->bitrate = 0;
} else {
/* Value in header is in units of 400 bps */
seqhdr->bitrate = seqhdr->bitrate_value * 400;
}
READ_UINT8 (&br, bits, 1);
if (bits != MARKER_BIT)
goto failed;
/* VBV buffer size */
READ_UINT16 (&br, seqhdr->vbv_buffer_size_value, 10);
/* constrained_parameters_flag */
READ_UINT8 (&br, seqhdr->constrained_parameters_flag, 1);
/* load_intra_quantiser_matrix */
READ_UINT8 (&br, seqhdr->load_intra_quantiser_matrix, 1);
if (seqhdr->load_intra_quantiser_matrix) {
gint i;
for (i = 0; i < 64; i++)
READ_UINT8 (&br, seqhdr->intra_quantizer_matrix[i], 8);
} else
memcpy (seqhdr->intra_quantizer_matrix, default_intra_quantizer_matrix, 64);
/* non intra quantizer matrix */
READ_UINT8 (&br, seqhdr->load_non_intra_quantiser_matrix, 1);
if (seqhdr->load_non_intra_quantiser_matrix) {
gint i;
for (i = 0; i < 64; i++)
READ_UINT8 (&br, seqhdr->non_intra_quantizer_matrix[i], 8);
} else
memset (seqhdr->non_intra_quantizer_matrix, 16, 64);
/* dump some info */
GST_LOG ("width x height: %d x %d", seqhdr->width, seqhdr->height);
GST_LOG ("fps: %d/%d", seqhdr->fps_n, seqhdr->fps_d);
GST_LOG ("par: %d/%d", seqhdr->par_w, seqhdr->par_h);
GST_LOG ("bitrate: %d", seqhdr->bitrate);
return TRUE;
/* ERRORS */
failed:
{
GST_WARNING ("Failed to parse sequence header");
/* clear out stuff */
memset (seqhdr, 0, sizeof (*seqhdr));
return FALSE;
}
}
/**
* gst_mpeg_video_packet_parse_sequence_extension:
* @packet: The #GstMpegVideoPacket that carries the data
* @seqext: (out): The #GstMpegVideoSequenceExt structure to fill
*
* Parses the @seqext MPEG Video Sequence Extension structure members
* from video @packet
*
* Returns: %TRUE if the seqext could be parsed correctly, %FALSE otherwise.
*
* Since: 1.2
*/
gboolean
gst_mpeg_video_packet_parse_sequence_extension (const GstMpegVideoPacket *
packet, GstMpegVideoSequenceExt * seqext)
{
GstBitReader br;
g_return_val_if_fail (seqext != NULL, FALSE);
if (packet->size < 6) {
GST_DEBUG ("not enough bytes to parse the extension");
return FALSE;
}
gst_bit_reader_init (&br, &packet->data[packet->offset], packet->size);
if (gst_bit_reader_get_bits_uint8_unchecked (&br, 4) !=
GST_MPEG_VIDEO_PACKET_EXT_SEQUENCE) {
GST_DEBUG ("Not parsing a sequence extension");
return FALSE;
}
/* skip profile and level escape bit */
seqext->profile_level_escape_bit =
gst_bit_reader_get_bits_uint8_unchecked (&br, 1);
seqext->profile = gst_bit_reader_get_bits_uint8_unchecked (&br, 3);
seqext->level = gst_bit_reader_get_bits_uint8_unchecked (&br, 4);
/* progressive */
seqext->progressive = gst_bit_reader_get_bits_uint8_unchecked (&br, 1);
/* chroma format */
seqext->chroma_format = gst_bit_reader_get_bits_uint8_unchecked (&br, 2);
/* resolution extension */
seqext->horiz_size_ext = gst_bit_reader_get_bits_uint8_unchecked (&br, 2);
seqext->vert_size_ext = gst_bit_reader_get_bits_uint8_unchecked (&br, 2);
seqext->bitrate_ext = gst_bit_reader_get_bits_uint16_unchecked (&br, 12);
/* skip marker bits */
gst_bit_reader_skip_unchecked (&br, 1);
seqext->vbv_buffer_size_extension =
gst_bit_reader_get_bits_uint8_unchecked (&br, 8);
seqext->low_delay = gst_bit_reader_get_bits_uint8_unchecked (&br, 1);
/* framerate extension */
seqext->fps_n_ext = gst_bit_reader_get_bits_uint8_unchecked (&br, 2);
seqext->fps_d_ext = gst_bit_reader_get_bits_uint8_unchecked (&br, 2);
return TRUE;
}
/**
* gst_mpeg_video_packet_parse_sequence_display_extension:
* @packet: The #GstMpegVideoPacket that carries the data
* @seqdisplayext: (out): The #GstMpegVideoSequenceDisplayExt
* structure to fill
*
* Parses the @seqext MPEG Video Sequence Display Extension structure
* members from video @packet
*
* Returns: %TRUE if the seqext could be parsed correctly, %FALSE otherwise.
*
* Since: 1.2
*/
gboolean
gst_mpeg_video_packet_parse_sequence_display_extension (const GstMpegVideoPacket
* packet, GstMpegVideoSequenceDisplayExt * seqdisplayext)
{
GstBitReader br;
g_return_val_if_fail (seqdisplayext != NULL, FALSE);
if (packet->size < 5) {
GST_DEBUG ("not enough bytes to parse the extension");
return FALSE;
}
gst_bit_reader_init (&br, &packet->data[packet->offset], packet->size);
if (gst_bit_reader_get_bits_uint8_unchecked (&br, 4) !=
GST_MPEG_VIDEO_PACKET_EXT_SEQUENCE_DISPLAY) {
GST_DEBUG ("Not parsing a sequence display extension");
return FALSE;
}
seqdisplayext->video_format =
gst_bit_reader_get_bits_uint8_unchecked (&br, 3);
seqdisplayext->colour_description_flag =
gst_bit_reader_get_bits_uint8_unchecked (&br, 1);
if (seqdisplayext->colour_description_flag) {
seqdisplayext->colour_primaries =
gst_bit_reader_get_bits_uint8_unchecked (&br, 8);
seqdisplayext->transfer_characteristics =
gst_bit_reader_get_bits_uint8_unchecked (&br, 8);
seqdisplayext->matrix_coefficients =
gst_bit_reader_get_bits_uint8_unchecked (&br, 8);
}
if (gst_bit_reader_get_remaining (&br) < 29) {
GST_DEBUG ("Not enough remaining bytes to parse the extension");
return FALSE;
}
seqdisplayext->display_horizontal_size =
gst_bit_reader_get_bits_uint16_unchecked (&br, 14);
/* skip marker bit */
gst_bit_reader_skip_unchecked (&br, 1);
seqdisplayext->display_vertical_size =
gst_bit_reader_get_bits_uint16_unchecked (&br, 14);
return TRUE;
}
/**
* gst_mpeg_video_packet_parse_sequence_scalable_extension:
* @packet: The #GstMpegVideoPacket that carries the data
* @seqscaleext: (out): The #GstMpegVideoSequenceScalableExt structure to fill
*
* Parses the @seqscaleext MPEG Video Sequence Scalable Extension structure
* members from video @packet
*
* Returns: %TRUE if the seqext could be parsed correctly, %FALSE otherwise.
*
* Since: 1.2
*/
gboolean
gst_mpeg_video_packet_parse_sequence_scalable_extension
(const GstMpegVideoPacket * packet,
GstMpegVideoSequenceScalableExt * seqscaleext)
{
GstBitReader br;
g_return_val_if_fail (seqscaleext != NULL, FALSE);
if (packet->size < 2) {
GST_DEBUG ("not enough bytes to parse the extension");
return FALSE;
}
gst_bit_reader_init (&br, &packet->data[packet->offset], packet->size);
if (gst_bit_reader_get_bits_uint8_unchecked (&br, 4) !=
GST_MPEG_VIDEO_PACKET_EXT_SEQUENCE_SCALABLE) {
GST_DEBUG ("Not parsing a sequence scalable extension");
return FALSE;
}
READ_UINT8 (&br, seqscaleext->scalable_mode, 2);
READ_UINT8 (&br, seqscaleext->layer_id, 4);
if (seqscaleext->scalable_mode == GST_MPEG_VIDEO_SEQ_SCALABLE_MODE_SPATIAL) {
READ_UINT16 (&br, seqscaleext->lower_layer_prediction_horizontal_size, 14);
SKIP (&br, 1);
READ_UINT16 (&br, seqscaleext->lower_layer_prediction_vertical_size, 14);
READ_UINT8 (&br, seqscaleext->horizontal_subsampling_factor_m, 5);
READ_UINT8 (&br, seqscaleext->horizontal_subsampling_factor_n, 5);
READ_UINT8 (&br, seqscaleext->vertical_subsampling_factor_m, 5);
READ_UINT8 (&br, seqscaleext->vertical_subsampling_factor_n, 5);
}
if (seqscaleext->scalable_mode == GST_MPEG_VIDEO_SEQ_SCALABLE_MODE_TEMPORAL) {
READ_UINT8 (&br, seqscaleext->picture_mux_enable, 1);
if (seqscaleext->picture_mux_enable)
READ_UINT8 (&br, seqscaleext->mux_to_progressive_sequence, 1);
READ_UINT8 (&br, seqscaleext->picture_mux_order, 3);
READ_UINT8 (&br, seqscaleext->picture_mux_factor, 3);
}
return TRUE;
failed:
GST_WARNING ("error parsing \"Sequence Scalable Extension\"");
return FALSE;
}
gboolean
gst_mpeg_video_finalise_mpeg2_sequence_header (GstMpegVideoSequenceHdr * seqhdr,
GstMpegVideoSequenceExt * seqext,
GstMpegVideoSequenceDisplayExt * displayext)
{
guint32 w;
guint32 h;
if (seqext) {
seqhdr->fps_n = seqhdr->fps_n * (seqext->fps_n_ext + 1);
seqhdr->fps_d = seqhdr->fps_d * (seqext->fps_d_ext + 1);
/* Extend width and height to 14 bits by adding the extension bits */
seqhdr->width |= (seqext->horiz_size_ext << 12);
seqhdr->height |= (seqext->vert_size_ext << 12);
seqhdr->bitrate += (seqext->bitrate_ext << 18) * 400;
}
w = seqhdr->width;
h = seqhdr->height;
if (displayext) {
/* Use the display size for calculating PAR when display ext present.
* But we are handling this like what DVD players are doing. Which means,
* ignore the display extension values if they are greater than the width/height
* values provided by seqhdr and calculate the PAR based on the seqhdr values. */
if (displayext->display_horizontal_size < w)
w = displayext->display_horizontal_size;
if (displayext->display_vertical_size < h)
h = displayext->display_vertical_size;
}
/* Pixel_width = DAR_width * display_vertical_size */
/* Pixel_height = DAR_height * display_horizontal_size */
switch (seqhdr->aspect_ratio_info) {
case 0x01: /* Square pixels */
seqhdr->par_w = seqhdr->par_h = 1;
break;
case 0x02: /* 3:4 DAR = 4:3 pixels */
seqhdr->par_w = 4 * h;
seqhdr->par_h = 3 * w;
break;
case 0x03: /* 9:16 DAR */
seqhdr->par_w = 16 * h;
seqhdr->par_h = 9 * w;
break;
case 0x04: /* 1:2.21 DAR */
seqhdr->par_w = 221 * h;
seqhdr->par_h = 100 * w;
break;
default:
GST_DEBUG ("unknown/invalid aspect_ratio_information %d",
seqhdr->aspect_ratio_info);
break;
}
return TRUE;
}
/**
* gst_mpeg_video_packet_parse_quant_matrix_extension:
* @packet: The #GstMpegVideoPacket that carries the data
* @quant: (out): The #GstMpegVideoQuantMatrixExt structure to fill
*
* Parses the @quant MPEG Video Quantization Matrix Extension
* structure members from video @packet
*
* Returns: %TRUE if the quant matrix extension could be parsed correctly,
* %FALSE otherwise.
*
* Since: 1.2
*/
gboolean
gst_mpeg_video_packet_parse_quant_matrix_extension (const GstMpegVideoPacket *
packet, GstMpegVideoQuantMatrixExt * quant)
{
guint8 i;
GstBitReader br;
g_return_val_if_fail (quant != NULL, FALSE);
if (packet->size < 1) {
GST_DEBUG ("not enough bytes to parse the extension");
return FALSE;
}
gst_bit_reader_init (&br, &packet->data[packet->offset], packet->size);
if (gst_bit_reader_get_bits_uint8_unchecked (&br, 4) !=
GST_MPEG_VIDEO_PACKET_EXT_QUANT_MATRIX) {
GST_DEBUG ("Not parsing a quant matrix extension");
return FALSE;
}
READ_UINT8 (&br, quant->load_intra_quantiser_matrix, 1);
if (quant->load_intra_quantiser_matrix) {
for (i = 0; i < 64; i++) {
READ_UINT8 (&br, quant->intra_quantiser_matrix[i], 8);
}
}
READ_UINT8 (&br, quant->load_non_intra_quantiser_matrix, 1);
if (quant->load_non_intra_quantiser_matrix) {
for (i = 0; i < 64; i++) {
READ_UINT8 (&br, quant->non_intra_quantiser_matrix[i], 8);
}
}
READ_UINT8 (&br, quant->load_chroma_intra_quantiser_matrix, 1);
if (quant->load_chroma_intra_quantiser_matrix) {
for (i = 0; i < 64; i++) {
READ_UINT8 (&br, quant->chroma_intra_quantiser_matrix[i], 8);
}
}
READ_UINT8 (&br, quant->load_chroma_non_intra_quantiser_matrix, 1);
if (quant->load_chroma_non_intra_quantiser_matrix) {
for (i = 0; i < 64; i++) {
READ_UINT8 (&br, quant->chroma_non_intra_quantiser_matrix[i], 8);
}
}
return TRUE;
failed:
GST_WARNING ("error parsing \"Quant Matrix Extension\"");
return FALSE;
}
/**
* gst_mpeg_video_packet_parse_picture_extension:
* @packet: The #GstMpegVideoPacket that carries the data
* @ext: (out): The #GstMpegVideoPictureExt structure to fill
*
* Parse the @ext MPEG Video Picture Extension structure members from
* video @packet
*
* Returns: %TRUE if the picture extension could be parsed correctly,
* %FALSE otherwise.
*
* Since: 1.2
*/
gboolean
gst_mpeg_video_packet_parse_picture_extension (const GstMpegVideoPacket *
packet, GstMpegVideoPictureExt * ext)
{
GstBitReader br;
g_return_val_if_fail (ext != NULL, FALSE);
if (packet->size < 5)
return FALSE;
gst_bit_reader_init (&br, &packet->data[packet->offset], packet->size);
if (gst_bit_reader_get_bits_uint8_unchecked (&br, 4) !=
GST_MPEG_VIDEO_PACKET_EXT_PICTURE) {
GST_DEBUG ("Extension is not a picture extension");
return FALSE;
}
/* f_code */
READ_UINT8 (&br, ext->f_code[0][0], 4);
READ_UINT8 (&br, ext->f_code[0][1], 4);
READ_UINT8 (&br, ext->f_code[1][0], 4);
READ_UINT8 (&br, ext->f_code[1][1], 4);
/* intra DC precision */
READ_UINT8 (&br, ext->intra_dc_precision, 2);
/* picture structure */
READ_UINT8 (&br, ext->picture_structure, 2);
/* top field first */
READ_UINT8 (&br, ext->top_field_first, 1);
/* frame pred frame dct */
READ_UINT8 (&br, ext->frame_pred_frame_dct, 1);
/* concealment motion vectors */
READ_UINT8 (&br, ext->concealment_motion_vectors, 1);
/* q scale type */
READ_UINT8 (&br, ext->q_scale_type, 1);
/* intra vlc format */
READ_UINT8 (&br, ext->intra_vlc_format, 1);
/* alternate scan */
READ_UINT8 (&br, ext->alternate_scan, 1);
/* repeat first field */
READ_UINT8 (&br, ext->repeat_first_field, 1);
/* chroma_420_type */
READ_UINT8 (&br, ext->chroma_420_type, 1);
/* progressive_frame */
READ_UINT8 (&br, ext->progressive_frame, 1);
/* composite display */
READ_UINT8 (&br, ext->composite_display, 1);
if (ext->composite_display) {
/* v axis */
READ_UINT8 (&br, ext->v_axis, 1);
/* field sequence */
READ_UINT8 (&br, ext->field_sequence, 3);
/* sub carrier */
READ_UINT8 (&br, ext->sub_carrier, 1);
/* burst amplitude */
READ_UINT8 (&br, ext->burst_amplitude, 7);
/* sub_carrier phase */
READ_UINT8 (&br, ext->sub_carrier_phase, 8);
}
return TRUE;
failed:
GST_WARNING ("error parsing \"Picture Coding Extension\"");
return FALSE;
}
/**
* gst_mpeg_video_packet_parse_picture_header:
* @packet: The #GstMpegVideoPacket that carries the data
* @pichdr: (out): The #GstMpegVideoPictureHdr structure to fill
*
* Parsers the @pichdr MPEG Video Picture Header structure members
* from video @packet
*
* Returns: %TRUE if the picture sequence could be parsed correctly, %FALSE
* otherwise.
*
* Since: 1.2
*/
gboolean
gst_mpeg_video_packet_parse_picture_header (const GstMpegVideoPacket * packet,
GstMpegVideoPictureHdr * hdr)
{
GstBitReader br;
if (packet->size < 4)
goto failed;
gst_bit_reader_init (&br, &packet->data[packet->offset], packet->size);
/* temperal sequence number */
if (!gst_bit_reader_get_bits_uint16 (&br, &hdr->tsn, 10))
goto failed;
/* frame type */
if (!gst_bit_reader_get_bits_uint8 (&br, (guint8 *) & hdr->pic_type, 3))
goto failed;
if (hdr->pic_type == 0 || hdr->pic_type > 4)
goto bad_pic_type; /* Corrupted picture packet */
/* VBV delay */
if (!gst_bit_reader_get_bits_uint16 (&br, &hdr->vbv_delay, 16))
goto failed;
if (hdr->pic_type == GST_MPEG_VIDEO_PICTURE_TYPE_P
|| hdr->pic_type == GST_MPEG_VIDEO_PICTURE_TYPE_B) {
READ_UINT8 (&br, hdr->full_pel_forward_vector, 1);
READ_UINT8 (&br, hdr->f_code[0][0], 3);
hdr->f_code[0][1] = hdr->f_code[0][0];
} else {
hdr->full_pel_forward_vector = 0;
hdr->f_code[0][0] = hdr->f_code[0][1] = 0;
}
if (hdr->pic_type == GST_MPEG_VIDEO_PICTURE_TYPE_B) {
READ_UINT8 (&br, hdr->full_pel_backward_vector, 1);
READ_UINT8 (&br, hdr->f_code[1][0], 3);
hdr->f_code[1][1] = hdr->f_code[1][0];
} else {
hdr->full_pel_backward_vector = 0;
hdr->f_code[1][0] = hdr->f_code[1][1] = 0;
}
return TRUE;
bad_pic_type:
{
GST_WARNING ("Unsupported picture type : %d", hdr->pic_type);
return FALSE;
}
failed:
{
GST_WARNING ("Not enough data to parse picture header");
return FALSE;
}
}
/**
* gst_mpeg_video_packet_parse_gop:
* @packet: The #GstMpegVideoPacket that carries the data
* @gop: (out): The #GstMpegVideoGop structure to fill
*
* Parses the @gop MPEG Video Group of Picture structure members from
* video @packet
*
* Returns: %TRUE if the gop could be parsed correctly, %FALSE otherwise.
*
* Since: 1.2
*/
gboolean
gst_mpeg_video_packet_parse_gop (const GstMpegVideoPacket * packet,
GstMpegVideoGop * gop)
{
GstBitReader br;
g_return_val_if_fail (gop != NULL, FALSE);
if (packet->size < 4)
return FALSE;
gst_bit_reader_init (&br, &packet->data[packet->offset], packet->size);
READ_UINT8 (&br, gop->drop_frame_flag, 1);
READ_UINT8 (&br, gop->hour, 5);
READ_UINT8 (&br, gop->minute, 6);
/* skip unused bit */
if (!gst_bit_reader_skip (&br, 1))
return FALSE;
READ_UINT8 (&br, gop->second, 6);
READ_UINT8 (&br, gop->frame, 6);
READ_UINT8 (&br, gop->closed_gop, 1);
READ_UINT8 (&br, gop->broken_link, 1);
return TRUE;
failed:
GST_WARNING ("error parsing \"GOP\"");
return FALSE;
}
/**
* gst_mpeg_video_packet_parse_slice_header:
* @packet: The #GstMpegVideoPacket that carries the data
* @slice_hdr: (out): The #GstMpegVideoSliceHdr structure to fill
* @seqhdr: The #GstMpegVideoSequenceHdr header
* @seqscaleext: The #GstMpegVideoSequenceScalableExt header
*
* Parses the @GstMpegVideoSliceHdr structure members from @data
*
* Returns: %TRUE if the slice could be parsed correctly, %FALSE otherwise.
*
* Since: 1.2
*/
gboolean
gst_mpeg_video_packet_parse_slice_header (const GstMpegVideoPacket * packet,
GstMpegVideoSliceHdr * slice_hdr, GstMpegVideoSequenceHdr * seqhdr,
GstMpegVideoSequenceScalableExt * seqscaleext)
{
GstBitReader br;
guint height;
guint mb_inc;
guint8 bits, extra_bits;
guint8 vertical_position, vertical_position_extension = 0;
g_return_val_if_fail (seqhdr != NULL, FALSE);
if (packet->size < 1)
return FALSE;
gst_bit_reader_init (&br, &packet->data[packet->offset], packet->size);
if (packet->type < GST_MPEG_VIDEO_PACKET_SLICE_MIN ||
packet->type > GST_MPEG_VIDEO_PACKET_SLICE_MAX) {
GST_DEBUG ("Not parsing a slice");
return FALSE;
}
vertical_position = packet->type - GST_MPEG_VIDEO_PACKET_SLICE_MIN;
height = seqhdr->height;
if (height > 2800)
READ_UINT8 (&br, vertical_position_extension, 3);
slice_hdr->vertical_position = packet->type;
slice_hdr->vertical_position_ext = vertical_position_extension;
if (seqscaleext)
if (seqscaleext->scalable_mode ==
GST_MPEG_VIDEO_SEQ_SCALABLE_MODE_DATA_PARTITIONING)
READ_UINT8 (&br, slice_hdr->priority_breakpoint, 7);
READ_UINT8 (&br, slice_hdr->quantiser_scale_code, 5);
READ_UINT8 (&br, slice_hdr->slice_ext_flag, 1);
if (!slice_hdr->slice_ext_flag)
slice_hdr->intra_slice = 0;
else {
READ_UINT8 (&br, slice_hdr->intra_slice, 1);
READ_UINT8 (&br, slice_hdr->slice_picture_id_enable, 1);
READ_UINT8 (&br, slice_hdr->slice_picture_id, 6);
READ_UINT8 (&br, bits, 1);
while (bits) {
READ_UINT8 (&br, extra_bits, 8);
READ_UINT8 (&br, bits, 1);
}
}
slice_hdr->header_size = gst_bit_reader_get_pos (&br);
if (height > 2800)
slice_hdr->mb_row = (vertical_position_extension << 7) + vertical_position;
else
slice_hdr->mb_row = vertical_position;
slice_hdr->mb_column = -1;
do {
if (!decode_vlc (&br, &mb_inc, mpeg2_mbaddr_vlc_table,
G_N_ELEMENTS (mpeg2_mbaddr_vlc_table))) {
GST_WARNING ("failed to decode first macroblock_address_increment");
goto failed;
}
slice_hdr->mb_column +=
mb_inc == GST_MPEG_VIDEO_MACROBLOCK_ESCAPE ? 33 : mb_inc;
} while (mb_inc == GST_MPEG_VIDEO_MACROBLOCK_ESCAPE);
return TRUE;
failed:
GST_WARNING ("error parsing \"Slice\"");
return FALSE;
}
/**
* gst_mpeg_video_quant_matrix_get_raster_from_zigzag:
* @out_quant: (out): The resulting quantization matrix
* @quant: The source quantization matrix
*
* Converts quantization matrix @quant from zigzag scan order to
* raster scan order and store the resulting factors into @out_quant.
*
* Note: it is an error to pass the same table in both @quant and
* @out_quant arguments.
*
* Since: 1.2
*/
void
gst_mpeg_video_quant_matrix_get_raster_from_zigzag (guint8 out_quant[64],
const guint8 quant[64])
{
guint i;
g_return_if_fail (out_quant != quant);
for (i = 0; i < 64; i++)
out_quant[mpeg_zigzag_8x8[i]] = quant[i];
}
/**
* gst_mpeg_video_quant_matrix_get_zigzag_from_raster:
* @out_quant: (out): The resulting quantization matrix
* @quant: The source quantization matrix
*
* Converts quantization matrix @quant from raster scan order to
* zigzag scan order and store the resulting factors into @out_quant.
*
* Note: it is an error to pass the same table in both @quant and
* @out_quant arguments.
*
* Since: 1.2
*/
void
gst_mpeg_video_quant_matrix_get_zigzag_from_raster (guint8 out_quant[64],
const guint8 quant[64])
{
guint i;
g_return_if_fail (out_quant != quant);
for (i = 0; i < 64; i++)
out_quant[i] = quant[mpeg_zigzag_8x8[i]];
}
Reference in a new issue View git blame Copy permalink